The same thing happened with Pavlik against Taylor. Get hit on the ear and you lose motor skills.

Roy's head was still fine, I mean he was covering up pretty good and he had his faculties. His legs were not under him and he could not throw anything back. he was trying to ride it out.

It sucks to be hit like that. Because your head remains fairly focused, but your body does not behave. I got hit like that once about 23 years ago. You literally feel weakness in your legs and arms like they have been almost disconnected.